Adjusting device for throttle valves



Nov. 14, 1944. O ALLEN 2,362,608

ADJUSTING DEVICE FOR THROTTLE VALVES Filed NOV. 10, 1942 INVENTOR- Eoy0.}! cm.

H \S ATTORNEY.

Patented Nov. 14, 1944 ADJUSTING liEVICE FOR THROTTLE VALVES Roy 0.Allen, Athens, Pa., assignor to Ingersoll- Rand Company, New York, N.'Y., a corporation of Newisrsey Application November 10, 1942, SerialNo. 465,146

1 Claim: ..('Cl. 251-137) This invention relates to pressure fluidcontrolling devices, and more particularly to an adjusting device forthrottle valves serving to control the power supply for a pneumaticallyactuated tool.

One object of the invention is to selectively vary the range of movementof the throttle valve.

Another object is to enable the adjustments required to so vary therange of movement of the throttle valve to be made without danger ofmarring the cooperating sealing surfaces of the throttle valve and itsseat.

Other objects will be in part obvious and in part pointed outhereinafter.

In the drawing accompanying this specification and in which similarreference numerals refer to similar parts,

Figure 1 is a side elevation, partly broken away, of a fluid actuatedtool having the invention applied thereto,

Figure 2 is a transverse view taken through Figure 1 n the line 2-2, and

Figure 3 is a plan view of a detail.

Referring more particularly to the drawing, 20 designates apneumatically actuated tool comprising a casing 2| having a laterallyextending grip portion 22 adjacent its rearward end whereby the tool maybe conveniently grasped for holding it in the correct relationship withthe work.

The casing 2| is suitably bored to accommodate a reciprocatory hammerpiston 23 that drives a working implement 24 and may be actuated bypressure fluid distributed to the opposite ends of the hammer piston 23by asuitable automatic valve 25.

The pressure fluid serving to operate the piston 23 passes through thegrip member 22 to the distributing valve 25. The grip member isaccordingly provided with a supply passage 25 having its outer endthreaded for connection with a supply conduit (not shown). The supplypassage 23 opens at its inner end into an annular groove .21 in the wallof a bore 28 in the grip member 22, and in the bore 28 is a sleeve 29having ports Within the sleeve 29, between the ports 30 and the passage32, is a beveled annular surface 33 to provide a seat for acorrespondingly shaped chamber 3| into the passage 32.

surface 34 of a reciprocatory throttle valve 35 that serves to controlthe flow of pressure fluid from the chamber 3| to the passage 32 and isnormally held against the surface 33 by a spring 36 within the chamber3|. One end of the spring 36 seats against the throttle valve and theother end seats against a plate 31 in a plug .38 threaded into the outerend of the bore 28 to form a closure therefor. The plug 38 is arrangedcoaxially with the sleeve 29 so-that its interior forms a continuationof the chamber 3| and has a head 39 that seats against the end of thegrip member 22.

The body portion of the throttle valve 35 is shown as being ofsubstantially disc shape. It has a depression 40 in one side to receivethe end of the spring 36, and on the opposite side of said valve areguide ribs 4| that cooperate slidably with the inner surface of thesleeve 29, adjacent the beveled surface 33, to maintain the throttlevalve coaxial with the surface 33.

The radial edges or surfaces 42 of the ribs 4| are inclined to defineV-shaped notches 43 through which pressure fluid flows from the Theapices of the notches 43 are pointed toward the chamber 3| so that theywill be the first portions of the notches to come into communicationwith the chamber 3| when the throttle valve is unseated. Owing to thisarrangement the flow area through the throttle valve may be. nicelycontrolled to permit only a small volume of pressure fluid to pass tothe percussive element of the tool for operating it to deliver lightblows against the working implement or, as when the throttle valve isopened to wide limits, a large volume of pressure fluid may be deliveredto the tool for operating it at a high rate of speed and with maximumforce.

The means serving to unseat the throttle valve is actuated by manualpressure and comprises a push rod 44 that is slidable in the grip member22 and seats at one end upon the inner ends of the ribs 4| of thethrottle valve. The opposite end of the push rod 44 lies within a recess45 in the grip member containing a rocker 46 that is pivoted at itslower end upon a pin 41 and has a laterally extending arm 48intermediate its ends to engage the upper end of the push rod 44.

The opposite or free end 49 of the rocker arm 48 extends into a slot 50in the inner end of a plunger 5| slidable transversely of the gripmember 22 for imparting movement to the rocker 46 to unseat the valve35. A pin 52 extends transversely through the innermost end of theplunger and through the slot 55 toprevent disconnection of the plunger5| from the rocker 45.

To the end that the plate 31 may be conveniently shifted endwise of thechamber 3| for varying the pressune of the spring 35 against thethrottle valve 35 said plate is provided on its outer surface with anexternally threaded stem 53 that engages a nut 54 in the head 39 of theplug 38. The nut 54 is freely rotatable in the head 39 and when rotatedin one direction or the other will cause the plate 31 to move toward oraway from the throttle valve for selectively increasing or decreasingthe force of the spring against said throttle valve.

The nut 54 is capable of only such endwise movement as will permit it torotate freely within the head 35 and carries on its inner end a flange55 that seats against the bottom of the chamber 3|. On a portion of thenut 54 lying exteriorly of the plug 38 is a collar 55 that is slidableendwise within a limited degree upon the nut 54 and carries a pin 51 toextend slidably into a slot 58 in the periphery of the nut 54 to preventrotation of the collar upon the nut.

The collar 55 is retained upon the nut 54 by, a the head 59 of a screw50 threaded into the end of the nut, and a suitable locking elementshown as being in the form of a spring pressed ball 5| in the head 39and enga ing depressions 62 in the adjacent surface of the collar 55holds the nut 54 normally stationary. v

In order to hold the plate 3! against rotary movement during therotation of the nut '54 for shifting the plate 31 axially of the chamber3| said plate is provided on its edge witha lug 63 to extend slidablyinto a key slot 54 in the inner surface of the plug 35, and on the innersurface of the plate 3'! is a stem 55 that extends through the spring 35to a point near the throttle valve 35 to serve as a stop for limitingthe unseating movement of the throttle valve.

In the operation of the device, whenever it is intended to cause thepneumatic tool to deliver light blows to the work, and in which case itis essential that a relatively small volume of power medium be deliveredto the percussive element of the tool, the nut 54 is manipulated toshift the plate 31 and thereby bring the-stem 55 to a position near thethrottle valve 35, 'I hus, when the throttle valve is pressed againstthe end of the stem 55 only so much of the V-shaped grooves 54 will bein communication with the chamber 3| as will define the required flowarea through'the throttle valve to assure the required action of thehammer piston 23.

If, on the other hand, the work requires the delivery of forceful blowsthereagainst by the percussive element of the tool, the nut 54 isrotated in an opposite hand direction to withdraw;

the stem 55 from the throttle valve 35. The latter may then be opened to,wider limits to assure deover, by slidably interlocking the plate 31with the casing portion of the tool so that the plate 31, the spring 35and the throttle valve are prevented from rotating during the turning ofthe nut 54 the throttle valve and its seat will be protected againstdamage other than that which may result from normal use.

I claim:

' An adjusting device for a throttle valve, com- I prising a casinghaving a passage for pressure fluid, an annular beveled seating surfacein the passage, a reciprocatory throttle valve having a surfacecorresponding with the seating surface and cooperating therewith tocontrol the passage, there being a recess in the throttle valve oppositethe last mentioned surface, manually operable means for unseating thethrottle valve, a hollow plug threaded into the casing in axialalignment with the seating surface, a, spring extending into the recessto resist unseating movement of the throttle valve, a seat member forthe spring within the plug and slidably interlockedwith the plug, a nut.rotatable in the plug and threadedly connected with the seat member foreffecting sliding movement of the seat member to vary the resistance ofthe spring, and a stem on the seat member extending through the springinto the path of the throttle valve for limiting the unseating movementof the throttle valve.

[ROY O. ALLEN.

